Optical contact module

ABSTRACT

The present invention relates to an optical contact module. The optical contact module comprises an optical device receiving member ( 20 ) including an optical device receiving portion ( 21 ) formed with an optical device receiving space for receiving an optical device therein, an optical fiber receiving portion ( 23 ) formed with an optical fiber receiving space for receiving an optical fiber therein, a contact hole ( 22 ) for communicating the optical device receiving portion ( 21 ) with the optical fiber receiving portion ( 23 ), a slit ( 27 ) formed on the optical fiber receiving portion ( 23 ) and a projection portion extended from the distal end of the optical device receiving portion; an optical fiber fixing cap ( 10 ) including a receiving portion ( 13 ), and a through-hole ( 12 ); and a fastening means for detachably fastening the optical fiber fixing cap ( 10 ) to the optical device receiving member ( 20 ).

This application is a 371 of PCT/KR03/02429, filed Nov. 12, 2003.

FIELD OF THE INVENTION

The present invention relates to an optical contact module, and moreparticularly, to an optical contact module capable of easily connectinga single optical fiber for transmitting an optical signal with anoptical transmission terminal or an optical reception terminal in such amanner that the optical signal does not leak.

BACKGROUND

Generally, an optical fiber comprises a core through which an opticalsignal is transmitted, a clad for enclosing the core, and a sheath layerfor protecting the core and the clad.

In a case where a single optical fiber is used for a security system,the optical fiber is installed to measure dynamic or static changes inan optical signal transmitted through the optical fiber, or to measurephysical fluctuation in the optical fiber using back scattering of theoptical signal.

A technique regarding a security system using an optical fiber isdisclosed in PCT Application No. PCT/KR02/0164 entitled “Security SystemUsing Optical Fiber and Method of Controlling the Same” and filed onAug. 30, 2002 by the present applicant. Particularly, when the opticalfiber is connected to an optical transmitter module and an opticalreceiver module in the invention of this application, an optical contactmeans capable of easily connecting optical fibers that have been cut tohave appropriate lengths in place is required.

Further, the optical contact means for use in such a security system isrequired to have the function of avoiding optical loss and shieldingnoises from the outside by completely sealing a contact portion.

Moreover, the optical contact means for use in such a security system isrequired to have the function of protecting the security system in sucha manner that when external force exceeding a predetermined value isapplied to the optical fiber, the optical fiber is easily separated fromthe security system to prevent the security system from being damaged.

Further, the optical contact means for use in such a security system isrequired to have the function of allowing a damaged or antiquatedoptical fiber to be easily replaced and reinstalled from the outside.

However, since the conventional optical contact means has a structurefor fixing the optical fiber by compressing a sheath of the opticalfiber with a metal piece, inexact dimensions of the metal piece maydamage the core or clad of the optical fiber. Therefore, there is aproblem that since the metal piece should be precisely machined,manufacturing costs thereof are increased.

Furthermore, there is a problem that if the optical contact means ismolded with synthetic resin or the like to be completely sealed, it isimpossible to properly adjust the length of the optical fiber andreinstall the optical fiber according to installation conditions.

SUMMARY

The present invention is conceived to solve the problems of theconventional optical contact means. Accordingly, an object of thepresent invention is to provide an optical fiber contact means havingthe functions required upon connection of optical fibers in a securitysystem employing optical fibers that has been proposed by the presentapplicant.

Specifically, an object of the present invention is to provide anoptical contact module capable of easily connecting optical fibers cutto have proper lengths in place, avoiding optical loss and shieldingnoises from the outside by completely sealing a contact portion,preventing a security system from being damaged by causing an opticalfiber to be easily separated from the security system if external forceexceeding a predetermined value is applied to the optical fiber,allowing a damaged or antiquated optical fiber to be easily replacedfrom the outside, and fixedly supporting the optical fiber withappropriate elastic force without damage to a core or clad of theoptical fiber.

The optical contact module of the present invention connects a singleoptical fiber for transmitting an optical signal to an optical devicesuch as a light emitting device or a light receiving device. The opticalcontact module comprises an optical device receiving member including anoptical device receiving portion formed with an optical device receivingspace for receiving the optical device therein from one end of theoptical device receiving member, an optical fiber receiving portionformed with an optical fiber receiving space for receiving an opticalfiber therein from the other end thereof, a contact hole having apredetermined diameter to communicate the optical device receivingportion with the optical fiber receiving portion, and a slit formed inthe optical fiber receiving portion by removing a portion of an outerperiphery of the optical fiber receiving portion by a predeterminedlength from the other end; an optical fiber fixing cap including areceiving portion which has a taper formed lengthwise such that theinner diameter of the receiving portion can be decreased to radiallypress the optical fiber receiving portion formed with the slit when theoptical fiber receiving portion of the optical device receiving memberis to be received therein from one end of the optical fiber fixing cap,and a through-hole at the other end thereof so that the optical fibercan be inserted into the receiving portion; and a fastening means formedon the outer periphery of the optical fiber receiving portion of theoptical device receiving member and on an inner periphery of thereceiving portion of the optical fiber fixing cap to detachably fastenthe optical fiber fixing cap to the optical device receiving member.

According to the present invention, when the optical fiber fixing cap iscoupled to the optical device receiving member, the slit formed in theoptical fiber receiving portion is compressed by the taper of theoptical fiber fixing cap, thereby fixing the optical fiber with elasticforce.

Preferably, the optical contact module further comprises a projectionportion extending lengthwise from a distal end of the optical devicereceiving portion of the optical device receiving member. The opticalfiber receiving portion of the optical device receiving member is formedwith a taper such that the outer diameter of the optical fiber receivingportion is increased from a distal end thereof, and a plurality of slitsare formed circumferentially at a predetermined interval in the opticalfiber receiving portion.

According to the present invention, the projection portion is insertedinto a groove of an optical transmitter module or an optical receivermodule to fix the optical device receiving member so that the opticaldevice receiving member does not rotate when the optical fiber fixingcap is coupled to the optical device receiving member, thereby ensuringeasy coupling of them.

Preferably, the optical contact module further comprises an opticalfiber supporting member which is made of an elastic material, has athrough-hole for receiving the optical fiber therein and is insertedinto the optical fiber receiving portion of the optical device receivingmember.

Preferably, a step is formed due to the outer diameter of the opticaldevice receiving portion of the optical device receiving member largerthan that of the optical fiber receiving portion thereof, and theoptical contact module further comprises an O-ring fitted around theouter periphery of the optical fiber receiving portion and interposedbetween the step and the optical fiber fixing cap.

According to the present invention, the optical fiber supporting membersupports the optical fiber without damage to a sheath of the optical,and alleviates differences in dimensions therebetween, and the O-ringprevents intrusion of raindrops from the outside.

Preferably, the fastening means comprises male threads formed on theouter periphery of the optical fiber receiving portion of the opticaldevice receiving member and female threads formed on the inner peripheryof the receiving portion of the optical fiber fixing cap.

Preferably, a pair of projection portions are formed on the opticaldevice receiving member.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of an optical contact module according toan embodiment of the present invention.

FIG. 2 is an exploded perspective view of the optical contact module ofFIG. 1.

FIG. 3 a is a sectional view taken along line A—A in FIG. 1.

FIG. 3 b is a sectional view taken along line A—A in another example ofthe optical contact module of FIG. 1.

FIG. 4 is an exploded perspective view of an optical contact moduleaccording to another embodiment of the present invention.

FIG. 5 a is a sectional view taken along line B—B in FIG. 4.

FIG. 5 b is a sectional view taken along line B—B in another example ofthe optical contact module of FIG. 4.

FIG. 6 is a schematic view showing the constitution of a security systememploying an optical contact module according to an embodiment of thepresent invention.

FIG. 7 is a view showing a state where the security system employing theoptical contact module according to the embodiment of the presentinvention is used.

FIG. 8 a is an exploded perspective view of portion C in the securitysystem of FIG. 7.

FIG. 8 b is an exploded perspective view of portion C in another exampleof the security system of FIG. 7.

FIG. 9 a is a sectional view of portion C in the security system of FIG.7.

FIG. 9 b is a sectional view of portion C in the other example of thesecurity system of FIG. 7.

EXPLANATION OF REFERENCE NUMERALS FOR DESIGNATING MAIN COMPONENTS IN THEDRAWINGS

10: Optical fiber fixing cap 12: Through-hole

13: Receiving portion 15, 25: Taper

16: Female thread 17: Coupling groove

20: Optical device receiving member 21: Optical device receiving portion

22: Contact hole 23: Optical fiber receiving portion

24: Projection portion 26: Male thread

27: Slit 28: Coupling ridge

100: Optical contact module 110: Optical fiber supporting member

120: O-ring 220: Optical fiber

300: Control unit 400: Optical transmitter module

500: Optical receiver module

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be described indetail with reference to the accompanying drawings.

FIG. 1 is a perspective view of an optical contact module according toan embodiment of the present invention, FIG. 2 is an explodedperspective view of the optical contact module of FIG. 1, FIG. 3 a is asectional view taken along line A—A in FIG. 1, and FIG. 3 b is asectional view taken along line A—A in another example of the opticalcontact module of FIG. 1.

As shown in FIG. 1, the optical contact module according to theembodiment of the present invention comprises an optical devicereceiving member 20 for accommodating a light emitting device or a lightreceiving device, and an optical fiber fixing cap 10 that is fastened tothe optical device receiving member 20 and fixes an optical fiber.

As shown in FIGS. 2 and 3, the optical device receiving member 20 has anoptical device receiving portion 21 extending from one end into theoptical device receiving member to receive the light emitting device orthe light receiving device, and further has an optical fiber receivingportion 23 extending by a predetermined length from the other end intothe optical device receiving member to receive an optical fiber. Asingle optical fiber, preferably, a plastic optical fiber is used as theoptical fiber. Further, an contact hole 22 with a predetermined diameteris formed to communicate the optical device receiving portion 21 withthe optical fiber receiving portion 23, so that when the optical devicereceived in the optical device receiving portion 21 is a light emittingdevice, light or an optical signal output from the light emitting deviceis transmitted to the optical fiber received in the optical fiberreceiving portion 23, while when the optical device received in theoptical device receiving portion 21 is a light receiving device, anoptical signal from the optical fiber received in the optical fiberreceiving portion 23 is transmitted to the light receiving devicereceived in the optical device receiving portion 21. Of course, aportion of an end of the optical fiber may be inserted into the contacthole upon actual installation of the optical fiber. Further, aprojection portion 24 extending lengthwise from the end of the opticaldevice receiving portion 21 is additionally provided so that the opticalcontact module 100 can be inserted into a substrate of an opticaltransceiver module to be described later. Moreover, the optical fiberreceiving portion 23 is formed with a taper 25 such that the outerdiameter of the optical fiber receiving portion 23 can increase over apredetermined length from a distal end thereof. A plurality of slits 27are formed in the optical fiber receiving portion 23 by removing someportions of an outer periphery of the optical fiber receiving portion 23from the distal end thereof to have a length larger than that of thetaper 25. Male threads 26 are formed as a fastening means on the outerperiphery to be screwed into the optical fiber fixing cap 10. Meanwhile,one projection portion 24 can be provided as shown in FIG. 3 a, or apair of projection portions 24 may be provided to be caught in bothsides of the substrate of the optical transceiver module as shown inFIG. 3 b.

As shown in FIGS. 2 and 3, the optical fiber fixing cap 10 has areceiving portion 13 extending from one end into the optical fiberfixing cap to receive the optical fiber receiving portion 23 of theoptical device receiving member 20, and further has a throughhole 12 atthe other end thereof so that the optical fiber can pass through thereceiving portion 13. A taper 15 is formed lengthwise in the receivingportion 13 such that the inner diameter of the receiving portion can bedecreased. Thus, when the taper 15 comes into contact with the taper 25formed in the optical fiber receiving portion 23 of the optical devicereceiving member 20, the optical fiber receiving portion 23 with theslots 27 is radially pressed. Further, female threads 16 are formed as afastening means on an inner surface of the receiving portion 13 to beengaged with the male threads 26 formed in the optical fiber receivingportion 23.

The optical contact module may further comprise an optical fibersupporting member to be received in the optical fiber receiving portion23 to fix the optical fiber. The optical fiber supporting member is madeof rubber or the like that is an elastic material and has a through-holefor receiving the optical fiber therein.

Moreover, a step is formed due the outer diameter of the optical devicereceiving portion 21 of the optical device receiving member 20 largerthan that of the optical fiber receiving portion 23, and the opticalcontact module may further comprise an O-ring fitted around the outerperiphery of the optical fiber receiving portion 23 to be placed betweenthe step and the optical fiber fixing cap 10.

FIG. 4 is an exploded perspective view of an optical contact moduleaccording to another embodiment of the present invention, FIG. 5 a is asectional view taken along line B—B in FIG. 4, and FIG. 5 b is asectional view taken along line B—B in another example of the opticalcontact module of FIG. 4.

As shown in FIG. 4, the optical contact module 100 according to theother embodiment of the present invention comprises an optical devicereceiving member 20 for accommodating a light emitting device or a lightreceiving device, and an optical fiber fixing cap 10 that is fastened tothe optical device receiving member 20 and fixes an optical fiber. Asshown in FIG. 5, the optical device receiving member 20 is formed with acoupling ridge 28 having a predetermined height on the outer peripheryof the optical fiber receiving portion 23, and a coupling groove 17having a predetermined depth is formed in an inner surface of theoptical fiber fixing cap 10 to be coupled to the coupling ridge 28.Therefore, although the optical contact module 100 according to theother embodiment of the present invention does not have the male threads26 and the female threads 16 of the optical contact module of theprevious embodiment, the coupling groove 17 of the optical fiber fixingcap 10 and the coupling ridge 28 of the optical device receiving member20 are coupled to each other as a coupling means. The function of fixingand connecting the optical fiber is the same as the previous embodiment.Meanwhile, one projection portion 24 can be provided to be inserted intothe substrate of the optical transceiver as shown in FIG. 5 a, or a pairof projection portions may be provided to be caught in both sides of thesubstrate of the optical transceiver module as shown in FIG. 5 b.

The operation and effects of an optical contact module according to anembodiment of the present invention will be described hereinafter inconnection with a security system employing an optical fiber as anoptical fiber sensor.

FIG. 6 is a schematic view showing the constitution of a security systememploying an optical contact module according to an embodiment of thepresent invention, FIG. 7 is a view showing a state where the securitysystem employing the optical contact module according to the embodimentof the present invention is used, FIG. 8 a is an exploded perspectiveview of portion C in the security system of FIG. 7, FIG. 8 b is anexploded perspective view of portion C in another example of thesecurity system of FIG. 7, FIG. 9 a is a sectional view of portion C inthe security system of FIG. 7, and FIG. 9 b is a sectional view ofportion C in the other example of the security system of FIG. 7.

As shown in FIG. 6, the security system employing the optical contactmodule according to the embodiment of the present invention comprises anoptical transmitter module 400 for outputting a predetermined opticalsignal, an optical receiver module 500 for receiving the optical signaloutput from the optical transmitter module 400 and converting theoptical signal into a predetermined electric signal, an optical fiber200 for transmitting the optical signal, the optical contact module 100for connecting both ends of the optical fiber 200 to the opticaltransmitter module 400 and the optical receiver module 500,respectively, and a control unit 300 for controlling the opticaltransmitter module 400 and the optical receiver module 500.

As shown in FIG. 7, the optical transmitter module 400, the opticalcontact module 100, the optical fiber 200, the optical contact module100 and the optical receiver module 500 can be provided in pair andinstalled on the right and left sides of a window 310 or the like.Further, it will be apparent to those skilled in the art that aplurality of optical transmitter modules 400, optical contact modules100, optical fibers 200, optical contact modules 100 and opticalreceiver modules 500 may be connected in parallel to one another tomonitor a more wider range. FIG. 7 shows a state where a plurality ofoptical transmitter modules 400 and optical receiver modules 500 aremounted within an optical transmitter module case 320.

FIGS. 8 a to 9 b show portion C of FIG. 7 and illustrate the process ofconnecting the optical fiber 200 to the optical transmitter module 400using the optical contact module 100. The optical transmitter modulecase 320 comprises an exterior case 322 and a cover 321. For theconnection of the optical fiber, a substrate 130 of the opticaltransmitter module and the optical device receiving member 20 are firstinstalled on the exterior case 322, then an O-ring 120 is fitted and thecover 321 is placed. At this moment, a light emitting device 132 isinserted into the optical device receiving portion 21 of the opticaldevice receiving member 20. Further, since the projection portion 24formed on the optical device receiving member 20 is inserted into aninsertion groove 134 formed in the substrate 130 to be installed withinthe exterior case 322, as shown in FIGS. 8 a and 9 a, the optical devicereceiving member 20 does not rotate when the optical fiber fixing cap 10is rotated to be fastened to the optical device receiving member 20.Alternatively, as shown in FIGS. 8 b and 9 b, the pair of the projectionportions 24 formed on the optical device receiving member 20 can befastened to catching steps 135 formed on the optical transceiver module.Further, the O-ring 120 interposed between the cover 321 and the opticaldevice receiving member 20 prevents raindrops from penetrating into thecase. Next, a single optical fiber 220 is inserted into the through-holeof the optical fiber fixing cap 10 and the optical fiber supportingmember 110 is fitted around the inserted end of the optical fiber thatin turn is inserted into the optical fiber receiving portion 23 of theoptical device receiving member 20 through a hole of the cover.Thereafter, the female threads formed on the inner surface of theoptical fiber fixing cap 10 are screwed onto the male threads formed onthe outer periphery of the optical fiber receiving portion 23. At thistime, the taper in the optical fiber fixing cap proceeds while pressingthe tapered end of the optical fiber receiving portion 23, therebycompressing and fixing the sheath of the optical fiber.

As shown in FIGS. 9 a and 9 b, in a state where the optical fiber 200has been assembled and fixed in such a manner, a core 210 is positionedclose to the light emitting device 132 through the contact hole 22 toreceive light or an optical signal emitted from the light emittingdevice 132. Further, the optical fiber 200 passes through the opticalfiber supporting member 110, and the sheath 220 of the optical fiber ispressed and fixed within the optical fiber receiving portion 21 of theoptical device receiving member 20 having the slits 27 by means of theoptical fiber supporting member 110, and then further compressed whenthe optical fiber fixing cap 10 is screwed onto the optical devicereceiving member. Therefore, the optical fiber 200 is fixed bycompressing the sheath 220 without damaging the core 210 of the opticalfiber 200, the loss of the optical signal is avoided, and theintroduction of noises and foreign materials from the outside iseffectively prevented. Further, since the optical fiber can be cut andinstalled in place depending on the length required for an installationspace, it is possible to variously change the length of the opticalfiber depending on installation conditions.

INDUSTRIAL APPLICABILITY

As described above, the optical contact module of the present inventioncan easily connect optical fibers cut in desired lengths in place, andavoid optical loss and shield noises from the outside by completelysealing a contact portion. Further, the optical contact module of thepresent invention can prevent a security system from being damaged byallowing the optical fiber to be easily separated from the securitysystem if external force exceeding a predetermined value is applied tothe optical fiber, cause a damaged or antiquated optical fiber to beeasily replaced from the outside, and fixedly support the optical fiberwith appropriate elastic force without damage to a core or clad of theoptical fiber.

It is intended that the embodiments of the present invention describedabove and illustrated in the drawings should not be construed aslimiting the technical spirit of the present invention. The scope of thepresent invention is defined only by the appended claims. Those skilledin the art can make various changes and modifications thereto withoutdeparting from its true spirit. Therefore, various changes andmodifications obvious to those skilled in the art will fall within thescope of the present invention.

1. An optical contact module to be installed to an optical transceivermodule for connecting a single optical fiber for transmitting andreceiving an optical signal to and from an optical device, the opticalcontact module comprising: an optical device receiving member includingan optical device receiving portion formed with an optical devicereceiving space for receiving the optical device therein from one end ofthe optical device receiving member, an optical fiber receiving portionformed with an optical fiber receiving space for receiving an opticalfiber therein from the other end thereof, a contact hole having apredetermined diameter to communicate the optical device receivingportion with the optical fiber receiving portion, a slit formed in theoptical fiber receiving portion by removing a portion of an outerperiphery of the optical fiber receiving portion by a predeterminedlength from the other end, and a projection portion extended lengthwisefrom a portion of a distal end of the optical device receiving portionof the optical device receiving member, the projection portion beinginserted into an insertion groove formed on a substrate of the opticaltransceiver module for installing the optical contact module to theoptical transceiver module; an optical fiber fixing cap including areceiving portion which has a taper formed lengthwise such that theinner diameter of the receiving portion can be decreased to radiallypress the optical fiber receiving portion formed with the slit when theoptical fiber receiving portion of the optical device receiving memberis to be received therein from one end of the optical fiber fixing cap,and a through-hole at the other end thereof so that the optical fibercan be inserted into the receiving portion; and a fastening means formedon the outer periphery of the optical fiber receiving portion of theoptical device receiving member and on an inner periphery of thereceiving portion of the optical fiber fixing cap to detachably fastenthe optical fiber fixing cap to the optical device receiving member. 2.The optical contact module according to claim 1, wherein the opticalfiber receiving portion of the optical device receiving member is formedwith a taper such that the outer diameter of the optical fiber receivingportion is increased from a distal end thereof, and a plurality of slitsare formed circumferentially at a predetermined interval in the opticalfiber receiving portion.
 3. The optical contact module according toclaim 1, further comprising: an optical fiber supporting member which ismade of an elastic material, has a through-hole for receiving theoptical fiber therein and is inserted into the optical fiber receivingportion of the optical device receiving member.
 4. The optical contactmodule according to claim 1, wherein a step is formed due to the outerdiameter of the optical device receiving portion of the optical devicereceiving member larger than that of the optical fiber receiving portionthereof, and an O-ring fitted around the outer periphery of the opticalfiber receiving portion is interposed between the step and the opticalfiber fixing cap.
 5. The optical contact module according to claim 1,wherein the fastening means comprises male threads formed on the outerperiphery of the optical fiber receiving portion of the optical devicereceiving member and female threads formed on the inner periphery of thereceiving portion of the optical fiber fixing cap.
 6. The opticalcontact module according to claim 1, wherein the fastening meanscomprises an annular coupling ridge protruding from the outer peripheryof the optical fiber receiving portion of the optical device receivingmember, and a coupling groove formed on the inner periphery of thereceiving portion of the optical fiber fixing cap to receive thecoupling ridge.
 7. The optical contact module according to claim 1,wherein a pair of projection portions are formed on the optical devicereceiving member.
 8. The optical contact module according to claim 2,wherein a pair of projection portions are formed on the optical devicereceiving member.
 9. The optical contact module according to claim 3,wherein a pair of projection portions are formed on the optical devicereceiving member.
 10. The optical contact module according to claim 4,wherein a pair of projection portions are formed on the optical devicereceiving member.
 11. The optical contact module according to claim 5,wherein a pair of projection portions are formed on the optical devicereceiving member.
 12. The optical contact module according to claim 6,wherein a pair of projection portions are formed on the optical devicereceiving member.